Staff in the National Ambulance Service are to be balloted for strike action over a redeployment dispute.
The workers - represented by SIPTU - include paramedics, emergency medical technicians, controllers and patient transport service professionals.
The row centres on what the union calls the refusal of the HSE to implement two binding Labour Court recommendations.
The rulings relate to the redeployment of staff to suitable posts following the reduction in Ambulance Command and Control centres around the country.